This invention relates generally to lift systems, and more particularly to methods and systems for vehicle lift systems having two or more lifting capacities.
At least some known above grade vehicle lift systems, especially those designed for lifting vehicles to a maintenance height, include a pair of runway tracks for positioning the vehicle, a base member for supporting the vehicle and vehicle lift system, and an expandable linkage system usually powered by a hydraulic cylinder or lead screw driving member to provide a lifting force. A ramp leading to each of the runway tracks permits a vehicle to be driven onto the vehicle lift system prior to being lifted. A height of the vehicle lift system and the vehicle ground clearance generally determines the configuration of the ramp. In general it is desirable to have the lowered height of the vehicle lift system be as low as possible. A low lowered height permits vehicles with a lower ground clearance to be driven onto the vehicle lift system without having to use long approach ramps. A higher height vehicle lift system or a vehicle with a low ground clearance requires a longer less sloped ramp. A vehicle lift system configured to a relatively low height may be limited in lifting capacity, however due to the size limitations and orientation imposed on the actuating mechanism by the low height.
If a greater lifting capacity is needed, the lowered height of the vehicle lift system typically becomes greater. This increased height requires longer approach ramps. However, the dimensions of a garage or shop may preclude a long ramp approach to the vehicle lift system. Therefore, space limitations may effectively place a limitation on the practical height of the vehicle lift system in the fully lowered position.
Generally, the actuating mechanism and the expandable linkage system are located within the space defined by the runway and the base. Positioning the actuating mechanism and the expandable linkage system outside of this space tends to inhibit access of the technician to the area under the vehicle to be worked on.
A vehicle lift system having an actuating mechanism that is sized and positioned to accommodate such limitations may be of sufficient capacity to be able to lift relatively smaller vehicles, however, to increase the vehicle lift system efficiency, larger vehicles should be accommodated as well.
It is desired to have a vehicle lifting system that has both a low lowered height as well as a high lifting capacity.